Catheter with insert-molded microelectrode

ABSTRACT

An apparatus includes a catheter assembly for use in a medical procedure to conduct electrophysiological mapping. The catheter assembly includes a catheter having an end effector with a tip member. One or more insert-molded microelectrodes are located in the tip member of the end effector for conducting electrophysiological mapping. The insert-molded microelectrodes include a microelectrode and a composite that isolates the microelectrode from contact with the tip member.

PRIORITY

This application claims priority to U.S. Provisional Pat. App. No.62/901,285, entitled “Catheter with Insert-Molded Microelectrode,” filedSep. 17, 2019, the disclosure of which is incorporated by referenceherein in its entirety.

BACKGROUND

Cardiac arrhythmias, such as atrial fibrillation, occur when regions ofcardiac tissue abnormally conduct electric signals. Procedures fortreating arrhythmia include surgically disrupting the conducting pathwayfor such signals. By selectively ablating cardiac tissue by applicationof energy (e.g., alternating-current or direct-current energy), it maybe possible to cease or modify the propagation of unwanted electricalsignals from one portion of the heart to another. The ablation processmay provide a barrier to unwanted electrical pathways by creatingelectrically insulative lesions or scar tissue that effectively blockcommunication of aberrant electrical signals across the tissue.

In some procedures, a catheter with one or more electrodes may be usedto provide ablation within the cardiovascular system. The catheter maybe inserted into a major vein or artery (e.g., the femoral artery) andthen advanced to position the electrodes within the heart or in acardiovascular structure adjacent to the heart (e.g., the pulmonaryvein). The one or more electrodes may be placed in contact with cardiactissue or other vascular tissue and then activated with electricalenergy to thereby ablate the contacted tissue. In some cases, theelectrodes may be bipolar. In some other cases, a monopolar electrodemay be used in conjunction with a ground pad or other referenceelectrode that is in contact with the patient. Irrigation may be used todraw heat from ablating components of an ablation catheter; and toprevent the formation of blood clots near the ablation site.

Examples of ablation catheters are described in U.S. Pub. No.2013/0030426, entitled “Integrated Ablation System using Catheter withMultiple Irrigation Lumens,” published Jan. 31, 2013, the disclosure ofwhich is incorporated by reference herein, in its entirety; U.S. Pub.No. 2017/0312022, entitled “Irrigated Balloon Catheter with FlexibleCircuit Electrode Assembly,” published Nov. 2, 2017, the disclosure ofwhich is incorporated by reference herein, in its entirety; U.S. Pub.No. 2018/0071017, entitled “Ablation Catheter with a Flexible PrintedCircuit Board,” published Mar. 15, 2018, the disclosure of which isincorporated by reference herein, in its entirety; U.S. Pub. No.2018/0056038, entitled “Catheter with Bipole Electrode Spacer andRelated Methods,” published Mar. 1, 2018, the disclosure of which isincorporated by reference herein, in its entirety; U.S. Pat. No.10,130,422, entitled “Catheter with Soft Distal Tip for Mapping andAblating Tubular Region,” issued Nov. 20, 2018, the disclosure of whichis incorporated by reference herein, in its entirety; U.S. Pat. No.8,956,353, entitled “Electrode Irrigation Using Micro-Jets,” issued Feb.17, 2015, the disclosure of which is incorporated by reference herein,in its entirety; and U.S. Pat. No. 9,801,585, entitled“Electrocardiogram Noise Reduction,” issued Oct. 31, 2017, thedisclosure of which is incorporated by reference herein, in itsentirety.

Some catheter ablation procedures may be performed after usingelectrophysiology (EP) mapping to identify tissue regions that should betargeted for ablation. Such EP mapping may include the use of sensingelectrodes on a catheter (e.g., the same catheter that is used toperform the ablation or a dedicated mapping catheter). Such sensingelectrodes may monitor electrical signals emanating from conductiveendocardial tissues to pinpoint the location of aberrant conductivetissue sites that are responsible for the arrhythmia. Examples of an EPmapping system are described in U.S. Pat. No. 5,738,096, entitled“Cardiac Electromechanics,” issued Apr. 14, 1998, the disclosure ofwhich is incorporated by reference herein, in its entirety. Examples ofEP mapping catheters are described in U.S. Pat. No. 9,907,480, entitled“Catheter Spine Assembly with Closely-Spaced Bipole Microelectrodes,”issued Mar. 6, 2018, the disclosure of which is incorporated byreference herein, in its entirety; U.S. Pat. No. 10,130,422, entitled“Catheter with Soft Distal Tip for Mapping and Ablating Tubular Region,”issued Nov. 20, 2018, the disclosure of which is incorporated byreference herein, in its entirety; and U.S. Pub. No. 2018/0056038,entitled “Catheter with Bipole Electrode Spacer and Related Methods,”published Mar. 1, 2018, the disclosure of which is incorporated byreference herein, in its entirety.

When using an ablation catheter, it may be desirable to ensure that oneor more electrodes of the ablation catheter are sufficiently contactingtarget tissue. For instance, it may be desirable to ensure that the oneor more electrodes are contacting target tissue with enough force toeffectively apply RF ablation energy to the tissue; while not applying adegree of force that might tend to undesirably damage the tissue. Tothat end, it may be desirable to include one or more force sensors orpressure sensors to detect sufficient contact between one or moreelectrodes of an ablation catheter and target tissue. Another indirectmethod that could also employed is to monitor the impedance level on themicroelectrodes or tip dome to determine amount of tissue contact.

In addition to using force sensing or EP mapping, some catheter ablationprocedures may be performed using an image guided surgery (IGS) system.The IGS system may enable the physician to visually track the locationof the catheter within the patient, in relation to images of anatomicalstructures within the patient, in real time. Some systems may provide acombination of EP mapping and IGS functionalities, including the CARTO3® system by Biosense Webster, Inc. of Irvine, Calif. Examples ofcatheters that are configured for use with an IGS system are disclosedin U.S. Pat. No. 9,480,416, entitled “Signal Transmission Using CatheterBraid Wires,” issued Nov. 1, 2016, the disclosure of which isincorporated by reference herein, in its entirety; and various otherreferences that are cited herein.

While several catheter systems and methods have been made and used, itis believed that no one prior to the inventors has made or used theinvention described, illustrated and claimed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings and detailed description that follow are intended to bemerely illustrative and are not intended to limit the scope of theinvention as contemplated by the inventors.

FIG. 1 depicts a schematic view of a medical procedure in which acatheter of a catheter assembly is inserted in a patient;

FIG. 2 depicts a perspective view of a distal portion of the catheter ofFIG. 1, with additional components shown in schematic form;

FIG. 3 depicts a perspective view of the distal portion of the catheterof FIG. 1, with an outer sheath omitted to reveal internal components;

FIG. 4 depicts an exploded perspective view of the distal portion of thecatheter of FIG. 1;

FIG. 5 depicts an enlarged partial perspective view of the distal tipportion of the catheter of FIG. 1, showing an insert-moldedmicroelectrode;

FIG. 6 depicts a perspective view in cross section of the distal tipportion of the catheter of FIG. 5;

FIG. 7 depicts a perspective view of the distal portion of the catheterof FIG. 1, shown with a composite of the insert in phantom;

FIG. 8A depicts an enlarged partial side view in cross section of thedistal portion of the catheter of FIG. 5;

FIG. 8B depicts an enlarged partial side view in cross section ofanother exemplary distal portion of a catheter that can be used in placeof the catheter of FIG. 5;

FIG. 9A depicts a perspective view of the composite of the insert-moldedmicroelectrode;

FIG. 9B depicts a partial side view of the composite of theinsert-molded microelectrode of FIG. 9A;

FIG. 9C depicts a top view of the composite of the insert-moldedmicroelectrode of FIG. 9A;

FIG. 9D depicts a front view of the composite of the insert-moldedmicroelectrode of FIG. 9A;

FIG. 9E depicts a side view in cross section of the composite of theinsert-molded microelectrode of FIG. 9A taken along line 9E-9E of FIG.9C;

FIG. 10 depicts a schematic view of a method of attaching theinsert-molded microelectrode with the distal end of the catheter of FIG.1; and

FIG. 11 depicts a schematic view of an insert-molding system for use inmaking the insert-molded microelectrode of FIG. 5.

DETAILED DESCRIPTION FOR MODES OF CARRYING OUT THE INVENTION

The following description of certain examples of the invention shouldnot be used to limit the scope of the present invention. The drawings,which are not necessarily to scale, depict selected embodiments and arenot intended to limit the scope of the invention. The detaileddescription illustrates by way of example, not by way of limitation, theprinciples of the invention. Other examples, features, aspects,embodiments, and advantages of the invention will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out theinvention. As will be realized, the invention is capable of otherdifferent or equivalent aspects, all without departing from theinvention. Accordingly, the drawings and descriptions should be regardedas illustrative in nature and not restrictive.

Any one or more of the teachings, expressions, versions, examples, etc.described herein may be combined with any one or more of the otherteachings, expressions, versions, examples, etc. that are describedherein. The following-described teachings, expressions, versions,examples, etc. should therefore not be viewed in isolation relative toeach other. Various suitable ways in which the teachings herein may becombined will be readily apparent to those skilled in the art in view ofthe teachings herein. Such modifications and variations are intended tobe included within the scope of the claims.

As used herein, the terms “about” or “approximately” for any numericalvalues or ranges indicate a suitable dimensional tolerance that allowsthe part or collection of components to function for its intendedpurpose as described herein. More specifically, “about” or“approximately” may refer to the range of values ±10% of the recitedvalue, e.g. “about 90%” may refer to the range of values from 81% to99%. In addition, as used herein, the terms “patient,” “host,” “user,”and “subject” refer to any human or animal subject and are not intendedto limit the systems or methods to human use, although use of thesubject invention in a human patient represents a preferred embodiment.

I. Overview of Exemplary Ablation Catheter System

FIG. 1 shows an exemplary medical procedure and associated components ofa cardiac ablation catheter system that may be used to provide cardiacablation as referred to above. In particular, FIG. 1 shows a physician(PH) grasping a handle (110) of a catheter assembly (100), with an endeffector (140) of a catheter (120) (shown in FIGS. 2 and 4 but not shownin FIG. 1) of catheter assembly (100) disposed in a patient (PA) toablate tissue in or near the heart (H) of the patient (PA). Catheterassembly (100) includes handle (110), catheter (120) extending distallyfrom handle (110), end effector (140) located at a distal end ofcatheter (120), and a user input feature (190) located on handle. Asused herein, the term “ablate” is intended to cover eitherradio-frequency ablation or irreversible electroporation.

As will be described in greater detail below, end effector (140)includes various components configured to deliver electrical energy totargeted tissue sites, provide EP mapping functionality, track externalforces imparted on end effector (140), track the location of endeffector (140), and disperse irrigation fluid. As will also be describedin greater detail below, user input feature (190) is configured todeflect end effector (140) and a distal portion of catheter (120) awayfrom a central longitudinal axis (L-L) (FIGS. 3-4) defined by a proximalportion of catheter (120).

As shown in FIG. 2, catheter (120) includes an elongate flexible sheath(122), with end effector (140) being disposed at a distal end of sheath(122). End effector (140) and various components that are contained insheath (122) will be described in greater detail below. Catheterassembly (100) is coupled with a guidance and drive system (10) via acable (30). Catheter assembly (100) is also coupled with a fluid source(42) via a fluid conduit (40). A set of field generators (20) arepositioned underneath the patient (PA) and are coupled with guidance anddrive system (10) via another cable (22). Field generators (20) aremerely optional.

Guidance and drive system (10) of the present example include a console(12) and a display (18). Console (12) includes a first driver module(14) and a second driver module (16). First driver module (14) iscoupled with catheter assembly (100) via cable (30). In some variations,first driver module (14) is operable to receive EP mapping signalsobtained via microelectrodes (138) of end effector (140) as described ingreater detail below. Console (12) includes a processor (not shown) thatprocesses such EP mapping signals and thereby provides EP mapping as isknown in the art.

First driver module (14) of the present example is further operable toprovide RF power to a distal tip member (142) of end effector (140), aswill be described in greater detail below, to thereby ablate tissue.Second driver module (16) is coupled with field generators (20) viacable (22). Second driver module (16) is operable to activate fieldgenerators (20) to generate an alternating magnetic field around theheart (H) of the patient (PA). For instance, field generators (20) mayinclude coils that generate alternating magnetic fields in apredetermined working volume that contains the heart (H).

First driver module (14) is also operable to receive position indicativesignals from a navigation sensor assembly (150) in end effector (140).In such versions, the processor of console (12) is also operable toprocess the position indicative signals from navigation sensor assembly(150) to thereby determine the position of end effector (140) within thepatient (PA). As will be described in greater detail below, navigationsensor assembly (150) includes a pair of coils on respective panels(151) that are operable to generate signals that are indicative of theposition and orientation of end effector (140) within the patient (PA).The coils are configured to generate electrical signals in response tothe presence of an alternating electromagnetic field generated by fieldgenerators (20). Other components and techniques that may be used togenerate real-time position data associated with end effector (140) mayinclude wireless triangulation, acoustic tracking, optical tracking,inertial tracking, and the like. Alternatively, end effector (140) maylack a navigation sensor assembly (150).

Display (18) is coupled with the processor of console (12) and isoperable to render images of patient anatomy. Such images may be basedon a set of preoperatively or intraoperatively obtained images (e.g., aCT or MM scan, 3-D map, etc.). The views of patient anatomy providedthrough display (18) may also change dynamically based on signals fromnavigation sensor assembly (150) of end effector (140). For instance, asend effector (140) of catheter (120) moves within the patient (PA), thecorresponding position data from navigation sensor assembly (150) maycause the processor of console (12) to update the patient anatomy viewsin display (18) in real time to depict the regions of patient anatomyaround end effector (140) as end effector (140) moves within the patient(PA). Moreover, the processor of console (12) may drive display (18) toshow locations of aberrant conductive tissue sites, as detected viaelectrophysiological (EP) mapping with end effector (140) or asotherwise detected (e.g., using a dedicated EP mapping catheter, etc.).The processor of console (12) may also drive display (18) to superimposethe current location of end effector (140) on the images of thepatient's anatomy, such as by superimposing an illuminated dot, acrosshair, a graphical representation of end effector (140), or someother form of visual indication.

Fluid source (42) of the present example includes a bag containingsaline or some other suitable irrigation fluid. Conduit (40) includes aflexible tube that is further coupled with a pump (44), which isoperable to selectively drive fluid from fluid source (42) to catheterassembly (100). As described in greater detail below, such irrigationfluid may be expelled through openings (158) of distal tip member (142)of end effector (140). Such irrigation may be provided in any suitablefashion as will be apparent to those skilled in the art in view of theteachings herein.

II. Exemplary End Effector of Catheter Assembly

FIGS. 2-4 show exemplary components of end effector (140), and othercomponents of the distal portion of catheter (120), in greater detail.End effector (140) includes a distal tip member (142), a distal tip base(144), a distal circuit disk (146), a strain gauge assembly (148), anavigation sensor assembly (150), a distal spacer stack (152) of distalspacers (153), and a pair of proximal spacers (154). Distal tip member(142), distal tip base (144), distal circuit disk (146), strain gaugeassembly (148), navigation sensor assembly (150), distal spacer stack(152), and proximal spacers (154) are coaxially aligned with each otherand are stacked longitudinally so that these components (144-154) definea stacked circuit. A pair of push-pull cables (160, 170) and anirrigation tube (180) extend along the length of catheter (120) to reachend effector (140). Each of the foregoing components will be describedin greater detail below. Flexible sheath (122) surrounds all of theforegoing components except for distal tip member (142).

As shown in FIGS. 3-4, distal tip member (142) of the present example iselectrically conductive and includes a cylindraceous body (156) with adome tip. A plurality of openings (158) are formed through cylindraceousbody (156) and are in communication with the hollow interior of distaltip member (142). Openings (158) thus allow irrigation fluid to becommunicated from the interior of distal tip member (142) out throughcylindraceous body (156). Cylindraceous body (156) and the dome tip arealso operable to apply RF electrical energy to tissue to thereby ablatethe tissue. Such RF electrical energy may be communicated from firstdriver module (14) to the proximal-most spacer (154) via cable (30).Distal tip member (142) may also include one or more thermocouples thatare configured to provide temperature sensing capabilities.

As shown in FIGS. 3-4, distal tip member (142) of the present examplealso includes one or more EP mapping microelectrodes (138) mounted tocylindraceous body (156). EP mapping microelectrodes (138) areconfigured to pick up electrical potentials from tissue that comes intocontact with EP mapping microelectrodes (138). First driver module (14)may process the EP mapping signals and provide the physician (PH) withcorresponding feedback indicating the locations of aberrant electricalactivity in accordance with the teachings of various references citedherein. EP mapping microelectrodes (138) and related components will bedescribed in further detail below.

Strain gauge assembly (148) is positioned proximal to distal circuitdisk (146) and is configured to sense external forces that impingeagainst distal tip member (142). When distal tip member (142) encountersexternal forces (e.g., when distal tip member (142) is pressed againsttissue), those external forces are communicated from distal tip member(142) to distal tip base (144), to distal circuit disk (146), and tostrain gauge assembly (148) such that strain gauge may generate asuitable signal corresponding to the magnitude and direction of theexternal force.

Navigation sensor assembly (150) may generate signals indicating theposition and orientation of end effector (140) in three-dimensionalspace with substantial precision. The signals from navigation sensorassembly (150) may be communicated via other structures in the layersthat are proximal to strain navigation sensor assembly (150), eventuallyreaching first driver module (14) of console (12) via cable (30).

As noted above and as shown in FIGS. 1-2, cable (30) couples catheterassembly (100) with drive system (10). As shown in FIG. 3, wires (32) ofcable (30) extend along the length of catheter (120) to reach theproximal-most proximal spacer (154).

As also noted above, catheter assembly (100) is configured to enableirrigation fluid to be communicated from fluid source (42) to catheter(120) via fluid conduit (40), thereby providing expulsion of theirrigation fluid via openings (158) of distal tip member (142). In thepresent example, the fluid path for the irrigation fluid includes anirrigation tube (180), which is shown in FIGS. 3-4. The proximal end ofirrigation tube (180) is coupled with fluid conduit (40) (e.g., athandle (110) of catheter assembly (100)). Irrigation tube (180) extendsalong the length of catheter (120) to reach end effector (140). In someversions, irrigation fluid may be communicated from the distal end ofirrigation tube (180) through a central passageway formed by alignedcentral apertures of the features described above, ultimately reachingan interior (157) of distal tip member (142) via aperture (159) ofdistal tip base (144) prior to flowing out from openings (158).

As noted above, and as shown in FIGS. 2-4, catheter (100) of the presentexample further includes a pair of push-pull cables (160, 170).Push-pull cables (160, 170) enable the physician (PH) to selectivelydeflect end effector (140) laterally away from a longitudinal axis(L-L), thereby enabling the physician (PH) to actively steer endeffector (140) within the patient (PA). Various mechanisms that may beused to drive push-pull cables (160, 170) in a simultaneous,longitudinally-opposing fashion will be apparent to those skilled in theart in view of the teachings herein.

III. Exemplary Insert-Molded Microelectrode

FIGS. 5-7 illustrate insert-molded microelectrodes (200), which may alsobe referred to herein as inserts (200). Each insert-moldedmicroelectrode or insert (200) includes microelectrode (138) and acomposite (202). Microelectrodes (138) are constructed of aplatinum-iridium material in the present example, however, othersuitable materials may be used instead or as well. Composite (202) is anon-conductive material in the present example, which electricallyisolates microelectrodes (138) from cylindraceous body (156) of tipmember (142) of end effector (140). By way of example only, composite(202) may be formed of polycarbonate, PEEK (polyether etherketone),polyethylene, UHMWPE (ultra high weight molecular polyethylene), or ABS.Alternatively, composite (202) may be formed of any other suitablematerial(s) such as Ultem (polyetherimide), polysulfone or a hardelastomeric compound such as 65D Pebax.

Insert-molded microelectrodes (200) are located in tip member (142) ofend effector (140). Inserts (200) extend longitudinally and parallelwith longitudinal axis L-L in the present example, but in other examplesinserts (200) can have other orientations with respect to longitudinalaxis L-L. To accommodate insert-molded microelectrodes (200), tip member(142) includes bores (204). Tip member (142) also includes a shell (206)defining an outer surface of tip member (142). Bores (204) extendlongitudinally from and through shell (206) proximally toward handle(110) of catheter assembly (100), and each bore (204) is configured toreceive one insert-molded microelectrode (200). In the present example,end effector (140) is configured with three insert-moldedmicroelectrodes (200); however, in other versions, end effector (140)can be configured with greater or fewer insert-molded microelectrodes(200).

As mentioned above, tip member (142) includes cylindraceous body (156)such that an outer surface of shell (206) defines a contour.Insert-molded microelectrodes (200) are shaped to conform to thiscontour of the outer surface of shell (206) when insert-moldedmicroelectrodes are positioned within bores (204). In this manner,conforming to the contour of the outer surface of shell (206) can beunderstood to mean that a distal surface of inserts (200) follows or isflush with an adjacent distal surface of shell (206). In the illustratedversion of a conforming configuration, the outer surface of shell (206)includes a curved region (208) that extends circumferentially around tipmember (142). Bore (204) is positioned in curved region (208) with thedistal end of bore (204) located in curved region (208). Insert (200) isfurther positionable in bore (204) within curved region (208) with thedistal surface of insert (200) located in curved region (208). In thisexample, curved region (208), outer surface of shell (206), distalsurface of microelectrode (138), and distal surface of composite (202)have a curved parallel arrangement where the surfaces of each are curvedand parallel to one another.

Still referring to the example of FIGS. 5-7, microelectrode (138) ofinsert (200) has a distal surface (210) that protrudes distally from adistal surface (212) of composite (202) of insert (200). With thisconfiguration, distal surface (210) of microelectrode (138) is curvedand extends parallel with the contour of the outer surface of shell(206). Similarly, distal surface (212) of composite (202) is also curvedand extends parallel with the contour of the outer surface of shell(206). In this exemplary arrangement, distal surface (212) of composite(202) is recessed relative to the outer surface of shell (206), whiledistal surface (210) of microelectrode (138) is flush with the outersurface of shell (206). Also, as best seen in FIG. 6, in the presentexample within tip member (142), microelectrode (138) of insert (200)extends further proximally relative to composite (202) of insert (200).However, in other versions composite (202) may extend further or shorterwithin tip member (142) relative to microelectrode (138) than theconfiguration illustrated in FIG. 6.

FIG. 8A illustrates a cross section of a portion of a distal end of tipmember (142) of end effector (140). In the present example, an adhesive(214) is used for secure connection of insert-molded microelectrode(200) to bore (204) of tip member (142). As shown in the example of FIG.8A, adhesive (214) is located along an interior wall of tip member (142)that defines bore (204) and further contacts an outer wall of composite(202). In this manner, adhesive (214) is located between insert-moldedmicroelectrode (200) and tip member (142) to thereby attach thesecomponents together. While the present example shows adhesive (214)extending along all of the depicted length of bore (204) and insert(200), in other versions the adhesive (214) is applied to less than thislength. A suitable adhesive application in this respect will securelyretain insert-molded microelectrode (200) within bore (204) of tipmember (142).

In some other versions, adhesive (214) is omitted entirely. Forinstance, in one such other version without adhesive (214),insert-molded microelectrode (200) has an interference fit with bore(204) of tip member (142). In this manner, the respective sizes of bore(204) and insert (200) are such that there is engaging contact betweenthe inner surface of tip member (142) defining bore (204) and the outersurface of insert (200) when insert (200) is positioned within bore(204). Furthermore, in this arrangement, there is sufficient frictionalforce between bore (204) of tip member (142) and insert (200) tosecurely retain inserts (200) within bore (204) of tip member (142)without adhesive or other features.

In another exemplary version, where insert-molded microelectrodes can beused with or without adhesive for attachment with a tip member of acatheter end effector, a pair of engaging features are used. Forinstance, FIG. 8B illustrates a cross section of a distal end of anotherexemplary tip member (342) that can be used instead of tip member (142)with end effector (140). Tip member (342) includes a shell (306) havinga bore (304) configured to receive an insert-molded microelectrode(300). Bore (304) is configured with one or more engaging features(316). Furthermore, composite (302) of insert (300) is configured withone or more engaging features (318). Engaging features (316) areconfigured to engage with or connect with engaging features (318) tothereby connect or attach insert-molded microelectrode (300) with tipmember (342). In the present example, this connection betweeninsert-molded microelectrode (300) and tip member (342) is configured asa permanent connection. However, in other versions this connection maybe selective such that insert (300) can be removed from tip member (342)either with or without the use of special tools to accomplish suchremoval. In either case however, the connection between insert (300) andtip member (342) is configured to be stable during use such that insert(300) remains securely within bore (304).

In the present example of FIG. 8B, engaging features (316) of bore (304)are configured as semi-spherical recesses or cut-outs. Meanwhile,engaging features (318) of composite (302) are configured assemi-spherical protrusions. In this manner, engaging features (316) andengaging features (318) are complementary such that engaging features(316) are configured to receive engaging features (318) and in doing sodefine an interference or snap fit that secures insert-moldedmicroelectrode (300) to and with tip member (342). In the presentexample, engaging features (318) of insert (300) are resilient featuressuch that engaging feature (318) may compress slightly when insertinginsert-molded microelectrode (300) into bore (304) and then expand onceengaging feature (318) is seated or located within engaging feature(316). In this way, insert (300) includes a resilient feature configuredto engage with an interior wall of bore (304). In other versions,engaging features (316) and engaging features (318) have forms andshapes different than the semi-spherical recesses and protrusions shownin FIG. 8A.

FIGS. 9A-9E depict composite (202) or portions thereof. Composite (302)mentioned above would have the same construction and configurationexcept for the addition of engaging features (318) with composite (302).As shown in FIGS. 9A-9E, composite (202) includes an opening (216) wheremicroelectrode (138) resides after insert molding. Composite (202) alsohas a proximally extending cylindrical portion (218) where a proximalportion of microelectrode (138) resides after insert molding. As shownin the present example, opening (216) within cylindrical portion (218)has a smaller diameter than the diameter of opening (216) at the distalend of composite (202). After insert molding with microelectrode (138),composite (202) defines a flange (220) around the region of opening(216) where the smaller diameter begins. With this configuration,microelectrode (138) seats against flange (220) after insert molding. Asmentioned above, distal surface (212) of composite (202) has a curvedshaped in the present example such that distal surface (212) is parallelwith curved region (208) of tip member (142). Composite (202) isconstructed of a non-conductive material and is configured so thatmicroelectrode (138) is isolated from contact with tip member (142) asmentioned above. While the present example describes composite (202) asbeing formed during an insert-molded process using microelectrode (138),in some other versions, composite (202) can be formed separate frommicroelectrode (138) and thereafter joined or combined withmicroelectrode (138).

IV. Exemplary Method of Attaching a Microelectrode to an End Effector

FIG. 10 depicts an exemplary method (400) usable to make aninsert-molded microelectrode and attach the insert-molded microelectrodeto an end effector of a catheter such as end effector (140) of catheter(120). With method (400) begins with step (410) that includes placing amicroelectrode (138) within a mold. Thereafter, step (420) includesinjecting composite (202, 302) into the mold to create insert-moldedmicroelectrode (200, 300). With insert-molded microelectrode (200, 300)formed, step (430) includes locating insert-molded microelectrode (200,300) within bore (204, 304) of shell (206, 206) of tip member (142,342). Finally, step (440) includes securing insert-molded microelectrode(200, 300) within bore (204, 304). This securing step can be achieved invarious ways as described above and may include an adhesive applicationprior to step (430). Of course, as mentioned above, some versionswithout adhesive may instead incorporate engaging features (316, 318)with tip member (342) and composite (302) when fabricating thesecomponents. In view of the teachings herein, other actions within thesesteps or other steps that may be used as well or omitted will beapparent to those skilled in the art.

V. Exemplary System for Insert-Molded Microelectrodes

FIG. 11 depicts an exemplary system (500) usable with making aninsert-molded microelectrode such as insert-molded microelectrodes (200,300) described above. In system (500) of this example, microelectrode(138) is positionable within a mold (502) of an injection moldingmachine (504). With microelectrode (138) within mold (502), and withmold (502) positioned within injection molding machine (504), composite(202, 302) is added to an injection unit (506) of injection moldingmachine (504). Injection unit (506) directs composite (202, 302) intomold (502) where composite (202, 302) combines with microelectrode (138)to thereby form insert-molded microelectrode (200, 300). After formingand cooling such that composite (202, 302) is solid, mold (502) can beopened and insert-molded microelectrode (200, 300) removed from mold(502). Finishing processes can be conducted with insert-moldedmicroelectrode (200, 300) as needed or desired. With insert-moldedmicroelectrode fabricated, method (400) can be continued from step (430)to connect or attach insert-molded microelectrode (200, 300) with tipmember (142, 342) of end effector (140) of catheter (120) as describedabove. It should be noted that system (500) is merely exemplary, andother systems for fabricating insert-molded microelectrodes (200, 300)can be used and will be apparent to those skilled in the art in view ofthe teachings herein.

VI. Exemplary Combinations

The following examples relate to various non-exhaustive ways in whichthe teachings herein may be combined or applied. It should be understoodthat the following examples are not intended to restrict the coverage ofany claims that may be presented at any time in this application or insubsequent filings of this application. No disclaimer is intended. Thefollowing examples are being provided for nothing more than merelyillustrative purposes. It is contemplated that the various teachingsherein may be arranged and applied in numerous other ways. It is alsocontemplated that some variations may omit certain features referred toin the below examples. Therefore, none of the aspects or featuresreferred to below should be deemed critical unless otherwise explicitlyindicated as such at a later date by the inventors or by a successor ininterest to the inventors. If any claims are presented in thisapplication or in subsequent filings related to this application thatinclude additional features beyond those referred to below, thoseadditional features shall not be presumed to have been added for anyreason relating to patentability.

Example 1

An apparatus for use in a medical procedure to conductelectrophysiological mapping comprises a body and an end effectorconnected with a distal end of the body. The end effector includes a tipmember at the distal end of the end effector. The tip member has a shellthat defines an outer surface of the tip member. The tip member furtherhas a bore located in the outer surface of the shell. The end effectoralso includes an insert positionable within the bore of the tip member.The insert includes a microelectrode and a non-conductive compositeconfigured to act as a contact barrier between the microelectrode andthe shell. The insert is shaped to conform to a contour of the outersurface of the shell.

Example 2

The apparatus of Example 1, the bore of the tip member extendinglongitudinally in a proximal direction toward the body.

Example 3

The apparatus of any one or more of Example 1 through Example 2, themicroelectrode made from platinum-iridium.

Example 4

The apparatus of any one or more of Example 1 through Example 3, furthercomprising an adhesive configured to adhere the composite to the shell.

Example 5

The apparatus of any one or more of Example 1 through Example 3, theinsert further includes an engaging feature configured to engage with aninterior wall of the bore.

Example 6

The apparatus of Example 5, the engaging feature being resilient andmaking a snap-fit connection with the bore.

Example 7

The apparatus of any one or more of Example 5 through Example 6, theengaging feature being configured to engage with the bore to make apermanent connection between the insert and the shell.

Example 8

The apparatus of any one or more of Example 1 through Example 3 andExample 5 through Example 7, the insert being configured to connect withthe shell without the use of adhesive.

Example 9

The apparatus of any one or more of Example 1 through Example 8, themicroelectrode being insert-molded with the composite to form theinsert.

Example 10

The apparatus of any one or more of Example 1 through Example 9, the tipmember having a plurality of openings configured to deliver anirrigation fluid.

Example 11

The apparatus of any one or more of Example 1 through Example 10, thetip member being configured to deliver electrical energy to a targetsite.

Example 12

The apparatus of any one or more of Example 1 through Example 11, thebody defining a longitudinal axis, with the end effector beingconfigured to deflect away from the longitudinal axis.

Example 13

The apparatus of Example 12, further comprising a push-pull cableconfigured to guide the end effector and operable to deflect the endeffector away from the longitudinal axis.

Example 14

The apparatus of Example 12, further comprising a pair of push-pullcables configured to guide the end effector and operable to deflect theend effector away from the longitudinal axis.

Example 15

The apparatus of any one or more of Example 1 through Example 14, theouter surface of the shell including a curved region that extendscircumferentially around the tip member, the bore being positioned inthe curved region, and the insert being positionable in the bore withinthe curved region.

Example 16

The apparatus of any one or more of Example 1 through Example 15, theapparatus having multiple bores in the outer surface of the shell withmultiple inserts, each bore being configured to receive one of theinserts.

Example 17

The apparatus of Example 16, having a plurality of inserts configured asinsert-molded microelectrodes.

Example 18

The apparatus of any one or more of Example 1 through Example 17, themicroelectrode of the insert having a distal surface that protrudesdistally from a distal surface of the composite of the insert.

Example 19

The apparatus Example 18, the distal surface of the microelectrode beingcurved and extending parallel with the contour of the outer surface ofthe shell.

Example 20

The apparatus of any one or more of Example 18 through Example 19, thedistal surface of the composite being curved and extending parallel withthe contour of outer surface of the shell.

Example 21

The apparatus of any one or more of Example 18 through Example 20, thedistal surface of the composite being recessed relative to the outersurface of the shell.

Example 22

The apparatus of any one or more of Example 18 through Example 21, thedistal surface of the microelectrode extending flush with the outersurface of the shell.

Example 23

The apparatus of any one or more of Example 1 through Example 22, themicroelectrode of the insert extending further proximally relative tothe composite of the insert.

Example 24

A method for attaching a microelectrode with a medical instrument usedfor electrophysiological mapping comprises (a) placing a microelectrodewithin a mold; (b) injecting a composite into the mold to create aninsert-molded microelectrode formed of the microelectrode and thecomposite, the insert-molded microelectrode having an outer surface thatconforms to an outer surface of a shell of a tip member of an endeffector of the medical instrument; (c) locating the insert-moldedmicroelectrode within a bore of the shell of the tip member, the boreconfigured to receive the insert-molded microelectrode; and (d) securingthe insert-molded microelectrode within the bore.

Example 25

The method of Example 24, further comprising applying an adhesive to aselect one or both of an interior of the bore and an outer surface ofthe composite prior to locating the inset-molded electrode within thebore.

Example 26

The method of Example 24, the composite having a molded engaging featureconfigured to attach with a complementary engaging feature of the borefor securing the insert-molded microelectrode within the bore.

Example 27

The method of any one or more of Example 24 through Example 26, thelocating and the securing steps occurring substantiallycontemporaneously.

Example 28

The method of Example 24 accomplished using the apparatus of any one ormore of Example 1 through Example 23.

VII. Miscellaneous

Any of the instruments described herein may be cleaned and sterilizedbefore and/or after a procedure. In one sterilization technique, thedevice is placed in a closed and sealed container, such as a plastic orTYVEK bag. The container and device may then be placed in a field ofradiation that can penetrate the container, such as gamma radiation,x-rays, or high-energy electrons. The radiation may kill bacteria on thedevice and in the container. The sterilized device may then be stored inthe sterile container for later use. A device may also be sterilizedusing any other technique known in the art, including but not limited tobeta or gamma radiation, ethylene oxide, hydrogen peroxide, peraceticacid, and vapor phase sterilization, either with or without a gasplasma, or steam.

It should be understood that any of the examples described herein mayinclude various other features in addition to or in lieu of thosedescribed above. By way of example only, any of the examples describedherein may also include one or more of the various features disclosed inany of the various references that are incorporated by reference herein.

It should be understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Theabove-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those skilled in the art in view of the teachingsherein. Such modifications and variations are intended to be includedwithin the scope of the claims.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Having shown and described various versions of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one skilled in the artwithout departing from the scope of the present invention. Several ofsuch potential modifications have been mentioned, and others will beapparent to those skilled in the art. For instance, the examples,versions, geometrics, materials, dimensions, ratios, steps, and the likediscussed above are illustrative and are not required. Accordingly, thescope of the present invention should be considered in terms of thefollowing claims and is understood not to be limited to the details ofstructure and operation shown and described in the specification anddrawings.

I/We claim:
 1. An apparatus for use in a medical procedure to conductelectrophysiological mapping, the apparatus comprising: (a) a body; and(b) an end effector connected with a distal end of the body, the endeffector including: (i) a tip member at the distal end of the endeffector, the tip member having a shell that defines an outer surface ofthe tip member, the tip member further having a bore located in theouter surface of the shell, and (ii) an insert positionable within thebore of the tip member, the insert including a microelectrode and anon-conductive composite configured to act as a contact barrier betweenthe microelectrode and the shell, the insert shaped to conform to acontour of the outer surface of the shell.
 2. The apparatus of claim 1,the bore of the tip member extending longitudinally in a proximaldirection toward the body.
 3. The apparatus of claim 1, the insertfurther including an engaging feature configured to engage with aninterior wall of the bore.
 4. The apparatus of claim 3, the engagingfeature being resilient and making a snap-fit connection with the bore.5. The apparatus of claim 3, the engaging feature being configured toengage with the bore to make a permanent connection between the insertand the shell.
 6. The apparatus of claim 1, the insert being configuredto connect with the shell without the use of adhesive.
 7. The apparatusof claim 1, the microelectrode being insert-molded with the composite toform the insert.
 8. The apparatus of claim 1, the tip member having aplurality of openings configured to deliver an irrigation fluid.
 9. Theapparatus of claim 1, the tip member being configured to deliverelectrical energy to a target site.
 10. The apparatus of claim 1, thebody defining a longitudinal axis, with the end effector beingconfigured to deflect away from the longitudinal axis.
 11. The apparatusof claim 1, the outer surface of the shell including a curved regionthat extends circumferentially around the tip member, the bore beingpositioned in the curved region, and the insert being positionable inthe bore within the curved region.
 12. The apparatus of claim 1, theapparatus having multiple bores in the outer surface of the shell withmultiple inserts, each bore being configured to receive one of theinserts.
 13. The apparatus of claim 12 having a plurality of insertsconfigured as insert-molded microelectrodes.
 14. The apparatus of claim1, the microelectrode of the insert having a distal surface thatprotrudes distally from a distal surface of the composite of the insert.15. The apparatus of claim 14, the distal surface of the microelectrodebeing curved and extending parallel with the contour of the outersurface of the shell.
 16. The apparatus of claim 14, the distal surfaceof the composite being curved and extending parallel with the contour ofouter surface of the shell.
 17. The apparatus of claim 14, the distalsurface of the composite being recessed relative to the outer surface ofthe shell.
 18. The apparatus of claim 14, the distal surface of themicroelectrode extending flush with the outer surface of the shell. 19.The apparatus of claim 1, the microelectrode of the insert extendingfurther proximally relative to the composite of the insert.
 20. A methodfor attaching a microelectrode with a medical instrument used forelectrophysiological mapping, the method comprising: (a) placing amicroelectrode within a mold; (b) injecting a composite into the mold tocreate an insert-molded microelectrode formed of the microelectrode andthe composite, the insert-molded microelectrode having an outer surfacethat conforms to an outer surface of a shell of a tip member of an endeffector of the medical instrument; (c) locating the insert-moldedmicroelectrode within a bore of the shell of the tip member, the boreconfigured to receive the insert-molded microelectrode; and (d) securingthe insert-molded microelectrode within the bore.